My toppy 5800 started formatting the hard drive randomly until now it was infrequent enough to ignore.

It's always a mistake to ignore issues like this. Fixing PSUs at the first sign of problems saves money in the long run. Otherwise, you just let it get bad enough to potentially permanently damage other components.

Having said that, there is another problem that causes disk wipes when you're recording from channels with poor signal. Making sure you only have channels from a single transmitter and aggressive channel pruning can help with this. But it does sound as though you have a hardware problem in this case.